1. Field of the Invention
The invention relates to a device with a read head for magnetically recorded information in electronic data processing installations, in particular in document processing systems, where certain modular units generate magnetic interference fields in the region of the read head.
2. Brief Description of the Background of the Invention Including Prior Art
Magnetic coils, such as, for example, electromagnetic coils and motor coils, generate magnetic fields resulting in interference fields relative to magnetically recorded information with respect to read heads and influencing substantially the functioning of a magnetic read head. However, if a magnetic read head is to be employed instead of an optical read head, it is not possible to eliminate these interference fields in electronic data processing equipment such as, for example, in document processing systems, sorting systems, printers with readers and the like.
In so-called document processing systems, the so-called Magnetic Ink Character Recognition, MICR characters, are read at a reading speed of about 45 cm/sec, where magnetic interferences are noted in a particularly disadvantageous way. The step of shielding the device groups generating the interference fields does not result in a desired success because, on the one hand, a complete shielding is not possible and, on the other hand, the shielding measures themselves result in side effects of a larger equipment expenditure and of an undesirable thermal insulation of the modular units of the document processing system. A heating up of such equipment, however, is permissible only within certain limits. Therefore, a shielding of the modular units generating the magnetic interference fields is not a sufficient means to resolve the problem of magnetic interference fields.